This 1828 caricature shows a woman looking into a microscope to observe the monsters swimming in a drop of London water. In the 1820s, much of London’s drinking water came from the Thames River, which was heavily polluted by the city sewers that emptied into it. A Commission on the London Water Supply that was appointed to investigate this situation issued a report in 1828, which resulted in various improvements. The five water companies that served the north bank of the river upgraded the quality of their water by ...